JP2963493B2 - Method for producing poly-1-olefin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention The present invention magnesium - relates to a process for preparing poly-1-olefins using a Ziegler supported catalyst based on the alcoholate and TiCl _4.

PRIOR ART Magnesium - alcoholate and TiCl ₄ and a base to a broad molecular weight distribution using a Ziegler supported catalyst poly -1
-The process for producing olefins is prior art.

Magnesium alcoholate and titanium tetrachloride 50 to
This catalyst uses a catalyst which has reacted at 100 ° C., separated and washed the solid, heat treated the solid at 110-200 ° C. with the addition of TiCl ₄ and washed the solid thoroughly to produce a transition metal component. Certain methods are known (Canadian Patent
1,207,499).

Instead of tempering with the addition of TiCl ₄ ,
Except for the point that further heat-treated without the addition Rather, magnesium - similar methods using similar reaction products of alcoholates with TiCl ₄ is also known. This is followed by a sufficient extraction treatment followed by washing (US Pat. No. 4,447,58).
No. 7).

Both known catalyst systems have the disadvantage that their preparation produces large amounts of washing liquid which have to be worked up. Furthermore, these processes are time consuming.

The problem to be solved by the present invention is to find a process which makes it possible to produce known catalysts in a relatively short time, while saving raw materials and auxiliaries and avoiding disposal. That is.

The object of the present invention is to solve this problem by removing only a part of the soluble titanium compound contained in the solid after the first reaction step, and subjecting the solid to a heat treatment in a liquid phase having a low titanium content. It has been found that it can be achieved by attaching

The object of the present invention is therefore to formula R ⁴ —CH ＝ CH ₂ wherein R ⁴ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. The reaction product of a magnesium alcoholate and titanium tetrachloride (component a) at a temperature of from 20 to 200 ° C. and a pressure of from 0.5 to 50 bar in a suspension of the 1-olefin of the formula For the production of poly-1-olefins by polymerization in the presence of a catalyst comprising an organometallic compound of a Group I-III metal of the Periodic Table (component b) And titanium tetrachloride in a hydrocarbon at a temperature of 50-100 ° C., then a portion of the soluble components are separated off and the resulting solid is subjected to a second reaction stage at 110-200 ° C. The process for producing poly-1-olefins described above, characterized in that the polymerization is carried out in the presence of a catalyst which has produced component a) by subjecting it to a heat treatment at a temperature for 8 to 100 hours.

Component a) is prepared using magnesium alcoholate. This magnesium-alcoholate has the formula Mg (O
R ¹ ) (OR ² ) (wherein R ¹ and R ² may be the same or different and each is an alkyl group having 1 to 6 carbon atoms). You may.
Examples include Mg (OC ₂ H ₅ ) ₂ , Mg (OiC ₃ H ₇ ) ₂ , Mg (O
_{-N-C 3 H 7) 2} , Mg (O-n-C 4 H 9) 2, Mg (OCH 3 (OC
₂ H ₅₎ and Mg (OC ₂ H ₅₎ there is _{(O-n-C 3 H} 7). Formula Mg
(OR) _n X _{m wherein} X is a halogen atom, (SO ₄ ) _1/2 , O
H, (CO ₃ ) _1/2 , (PO ₄ ) _1/3 or Cl, R is as defined above and n + m is 2. It is also possible to use a simple magnesium alcoholate represented by the formula:

However, magnesium-alcolate complexes (comp
lex) can also be used. Magnesium alcoholate of this type of complex means a magnesium alcoholate containing, in addition to magnesium, at least one metal of Groups I to IV of the Periodic Table. Examples of magnesium-alcoholates of such complexes include [Mg (OiC ₃ H ₇ )
₄ ] Li ₂ , A ₂ (OiC ₃ H ₇ ) ₈ ] Mg, [Si ₂ (OC ₂ H
₅ ) ₆ ] Mg, [Mg (OC ₂ H ₅ ) ₃ ] Na, [A ₂ (Oi-
C ₄ H _{9) 8]} Mg and _[A 2 (O-Second -C ₄ H _{9) 6} (OC
There are ₂ H _{5) 2]} Mg. The magnesium-alcoholate (alkoxide salt) of the complex is produced by a known method. Examples of the preparation of the magnesium alcoholate of the complex are described below: 1. Two metal alcoholates can be reacted in a suitable solvent, for example: 2. Dissolve magnesium in alcoholic solution of metal alcoholate: 3. Dissolve two metals simultaneously in alcohol: Simple magnesium-alcoholates, especially Mg (OC
_{2 H 5) 2, Mg (} O-n-C 3 H 7) 2 and _{Mg (O-i-C 3} H
₇ ) ₂ is particularly preferred. Magnesium alcoholate is used in a pure state or supported on a carrier.

Component a) is prepared in two reaction stages at different temperatures.

In the first reaction stage, the magnesium alcoholate is reacted with titanium tetrachloride, preferably with stirring at a temperature of 50 to 100 ° C., in particular 60 to 90 ° C., in the presence of an inert hydrocarbon.
0.9 to 5 mol, in particular 1.4 to 3.5 mol, of titanium tetrachloride are used per mol of magnesium alcoholate.

Suitable inert hydrocarbons include aliphatic or cycloaliphatic hydrocarbons, such as butane, pentane, hexane, heptane,
Hydrogenated diesel oil fractions or gasoline fractions with isooctane, cyclohexane or methylcyclohexane, or aromatic hydrocarbons such as toluene or xylene, which have been carefully deprived of oxygen, sulfur compounds and moisture, can also be used.

The reaction time in the first stage is 0.5 to 8 hours, in particular 2 to 6 hours.
Time.

In the first reaction stage, a total exchange takes place between the alkoxy group of the magnesium-alcoholate and the chlorine atom of the titanium tetrachloride, the resulting reaction product being a hydrocarbon-insoluble solid containing magnesium and titanium and a hydrocarbon-insoluble solid. And soluble titanium-ester-chloride.

Next, a part of the unreacted soluble titanium compound is removed from the hydrocarbon-insoluble reaction product of magnesium-alcoholate and titanium tetrachloride. This can be done by washing with an inert hydrocarbon. In this way,
Part of the resulting titanium-ester-chloride remains in the solid, making it possible to control the extent to which component a) is coated with titanium. In some cases, it is also possible to remove all hydrocarbon-insoluble reaction products from the suspension medium containing the soluble titanium compound, for example by filtration. In this case, the amount of filtrate required to adjust component a) to such an extent that it is coated with titanium is added before the heat treatment.

In the second reaction stage, the resulting solid is stirred for 100-200
C., in particular at a temperature of from 110 to 160.degree. The reaction time is between 8 and 100 hours, in particular between 10 and 40 hours. At this stage, the solid is in a liquid phase with low titanium content. After this heat treatment, the solid phase of the suspension has the desired titanium content and the liquid phase of the resulting suspension is sufficiently low in titanium-containing compounds. The catalyst does not need to be washed.

This operation gives a hydrocarbon-insoluble solid containing magnesium and titanium, referred to as component a).

The polymerization catalyst used in the present invention comprises the component a) as an organometallic compound of a metal belonging to Groups I to III of the Periodic Table [Component b).
Manufactured by combining with

Component a) can be reacted directly with component b) as a suspension, but may first be isolated as a solid, stored and resuspended for later use.

It is advantageous to use organoaluminum compounds as component b). The organoaluminum compounds suitable organoaluminum compounds chlorinated dialkyl formula R ³ ₂ ACl ₃ - aluminum - alkyl represented by monochloride or formula R ³ ₂ A ₂ Cl - aluminum - sesquichloride is is there. However, in both of the above formulas, R ³ is an alkyl group having 1 to 16 carbon atoms. Examples which may be mentioned are (C ₂ H ₅ ) ₂ ACl, (i-C ₄ H ₉ ) ₂ ACl and (C ₂ H ₅ )
_{There is 3} A ₂ Cl ₃ . Mixtures of these compounds can also be used.

It is particularly advantageous to use chlorine-free compounds as organoaluminum compounds. The slight chlorine-free compounds suitable for this purpose, aluminum having a hydrocarbon group having 1 to 6 carbon atoms - trialkyl or aluminum - dialkyl halides, in particular _{A (i-C 4 H 9} ) 3 or A
_{(I-C 4 H 9)} 2 H and 4 to 20 carbon atoms diolefins, particularly reaction products of isoprene. An example which may be mentioned is aluminum-isoprenyl.

Other suitable chlorine-free organoaluminum compound aluminum - is hydrido - aluminum represented by trialkyl AR ³ ₃ or Formula AR ³ ₂ H - dialkyl.
However, in both of the above formulas, R ³ is an alkyl group having 1 to 16 carbon atoms. Examples include A (C ₂ H ₅ ) ₃ , A (C ₂ H ₅ ) ₂ H, A
_{(C 3 H 7) 3,} A (C 3 H 7) 2 H, A (i-C 4 H 9) 3, A
_{(I-C 4 H 9)} 2 H, A (C 8 H 17) 3, A (C 12 H 25)
_{3, A (C 2 H 5} ) (C 12 H 25) 2 and _{A (i-C 4 H 9} )
It is (C ₁₂ H _{25) 2.}

It is also possible to use mixtures of organometallic compounds of metals of groups I to III of the periodic table, in particular mixtures of different organoaluminum compounds.

The following mixtures may be mentioned as examples: A (C ₂
H _{5) 3} and _{A (i-C 4 H 9} ) 3, A (C 2 H 5) 2 Cl and A
(C ₈ H ₁₇ ) ₃ , A (C ₂ H ₅ ) ₃ and A (C ₈ H ₁₇ ) ₃ , A
(C ₄ H ₉ ) ₂ H and A (C ₈ H ₁₇ ) ₃ , A (i−C ₄ H ₉ ) ₃ and A (C ₈ H ₁₇ ) ₃ , A (C ₂ H ₅ ) ₃ and A (C
_{12 H 25) 3, A (} i-C 4 H 9) 3 and _{A (C 12 H 25) 3} A
(C ₂ H ₅ ) ₃ and A (C ₁₆ H ₃₃ ) ₃ , A (C ₃ H ₇ ) ₃ and A
(C ₁₈ H ₃₇ ) ₂ (i-C ₄ H ₉ ) and A (C ₂ H ₅ ) ₃ and aluminum-isoprenyl (isoprene and A (i-C
₄ H _{9) 3} or _{A (i-C 4 H 9} ) reaction products of ₂ H).

Components a) and b) are mixed in a stirred reactor at -30 before polymerization.
You may mix at the temperature of -150 degreeC, Preferably -10-120 degreeC. The two components are directly combined in a polymerization vessel for 20-20
The polymerization temperature may be 0 ° C. However, component b)
May be added in two stages, i.e. -30 to 15 before polymerization.
At a temperature of 0 ° C., component a) is preactivated with a portion of component b) and the remainder of component b) is introduced at a temperature of from 20 to 200 ° C. into the polymerization reactor.

The polymerization catalyst used according to the invention has the formula R ⁴ —CH ＝ CH ₂ wherein R ⁴ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. ] It is used for polymerizing 1-olefin represented by these.
Examples of the 1-olefin include ethylene, propylene,
There are butene-1, hexene-1, 4-methylpentene-1 and octene-1.

It is advantageous to polymerize ethylene itself or a mixture of at least 70% by weight of ethylene and up to 30% by weight of other 1-olefins of the above formula.

It is particularly advantageous to polymerize ethylene itself or a mixture of at least 90% by weight of ethylene and up to 10% by weight of other 1-olefins of the above formula.

As is known, the polymerization is carried out continuously or discontinuously in one or more stages in the solution, suspension or gas phase at from 20 to 200 ° C., in particular from 50 to 150 ° C. Pressure is 0.5
~ 50bar. Polymerization is of particular industrial interest5
It is advantageous to work within a pressure range of 3030 bar.

In this way, 0.00 component a) dispersing medium 1 dm ³ per or reaction vessel volume 1 dm ³ per titanium based
It is used at a concentration of from 01 to 1 mmol (Ti), in particular from 0.001 to 0.5 mmol (Ti). Organometallic compounds, dispersing medium 1 dm ³ per or reaction vessel volume 1 dm ³ per, 0.1 to 5 mmol, in particular 0.5~4mm
Use at a concentration of ol. However, higher concentrations are also possible in principle.

The suspension polymerization is carried out in an inert dispersion medium customary in the Ziegler low-pressure process, for example aliphatic or aromatic hydrocarbons. Examples of such hydrocarbons include butane, pentane, hexane, heptane, isooctane, cyclohexane and methylcyclohexane. oxygen,
Gasoline fractions or hydrogenated diesel oil fractions that have been carefully deprived of sulfur compounds and moisture can also be used.

The gas-phase polymerization can be carried out directly or after pre-polymerizing the catalyst by a suspension method.

The molecular weight of the polymer can be adjusted as known,
In particular, it is advantageous to use hydrogen for this purpose.

As a result of the high activity of the catalysts used, the process according to the invention leads to polymers of very low titanium and halogen content and therefore exhibits very good values in tarnish fastness and corrosion tests. Furthermore, the process of the invention allows the production of polymers with a very broad molecular weight distribution (polydispersity). That is, the _MW / _Mn value of this polymer is 10 or more.

Another important advantage of the process according to the invention can be seen in the fact that it is possible to easily produce polymers with very different molecular weight distributions by varying the hydrogen concentration. For example, when polymerized without hydrogen, a polymer having a molecular weight of more than 2 million is produced, and when polymerized with a hydrogen content of 70% by volume in the gas phase, a polymer having a molecular weight of about 30,000 is produced.

Polymers can be processed at high production rates into hollow bodies, tubes, cables and films having smooth surfaces by extrusion and extrusion blow molding processes.

Because of the special structure of the polymer, hollow bodies and bottles made from the polyolefin obtained according to the invention are characterized by being very resistant to stress crack formation.

Furthermore, in the case of suspension- and gas-phase polymerization, the process according to the invention makes it possible to produce free-flowing polymer powders having a high bulk density and to produce moldings directly without a granulation step. Subsequent processing can be performed.

Finally, in the process of the present invention, both the time taken to produce the catalyst and the amount of titanium-containing hydrocarbon solution obtained are reduced.
It is reduced by about 70%. Furthermore, 12% of the expensive titanium tetrachloride to be used in a conventional manner is saved.

[Examples] The present invention will be described in more detail with reference to the following examples.

In each case, the preparation and polymerization of the catalyst was carried out using a hydrogenated diesel oil cut in the boiling range of 130-170 ° C.

The titanium content of the catalyst was measured by colorimetry [Ref: GOMueller, “Praktikum der quantitativen”
chemischen Analyse "(Laboratory Manual for Quantitative Chemical Analysis), 4th Edition, (1957), p. 243].

The melt flow index (MFI) was determined according to DIN 53,735 (E).

_MW / _Mn values were determined from gel permeation chromatography fractionation data at 135 ° C using o-dichlorobenzene (ODCB) as solvent and eluent.

The viscosity number (VN) was measured according to DIN 53,728, page 4, using an Ubbelohde viscometer using decahydronaphthalene as a solvent.

The density is according to DIN 53,479 and the bulk density is DIN 53,468
It was measured according to.

Example 1 a) component a manufacturing dropping funnel, a stirrer, a reflux condenser and magnesium 114.3g in 4-neck, round bottom flask 2 dm ³ equipped with a thermometer - ethylated of 1 dm ³ diesel oil fraction in In an N ₂ atmosphere. 332 g of TiCl ₄ are added dropwise to this dispersion over 5.5 hours. After the solid has settled, the 0.5 dm ³ supernatant solution is removed at 60 ° C. and 1.1 dm ³ of fresh dispersion medium is added. After a total of four replenishments of 1.1 dm ³ of dispersion medium and each time again taking off 1.1 dm ³ of the supernatant solution, 0.5 dm ³ of dispersion medium is replenished and the suspension is stirred at 125 ° C. for 16 hours. I do. The that time supernatant solution contains less Ti than 1 dm ³ per 10 mmol. The solid (component a) has the following analytical composition: Ti 6.2% by weight Mg 70.8% by weight Cl 23.0% by weight b) Preactivation of component a) 30 g of component a) in 0.150 dm ³ with diesel oil And 36 cm ³ of a 1 molar solution of triethylaluminum are added. The mixture was stirred at 120 ° C. for 2 hours, after which 85% of titanium (IV) had been reduced to titanium (III).

c) Polymerization of ethylene in suspension 0.75 dm ³ of hydrocarbon, 5 mmol of aluminum-isoprenyl and 0.8 mg of component a) are placed in a 1.5 dm ³ steel autoclave. 3.2 bar of H ₂ and 3.9 bar of ethylene are introduced under pressure at a polymerization temperature of 85 ° C. Ethylene is then metered in to maintain total pressure. The experiment is stopped after 2 hours. The polymer is separated by filtration and dried in a vacuum drying cabinet. 147 g of polymer are obtained. This corresponds to a catalyst-time yield of 9.8 kg (PE) / mmol (Ti) .h. The polymer has a melt flow index MFI 190/5 and a melt flow index ratio of 12.3 to MFI 190/5 with a melt flow index of 2.5 g / 10 min. M _W / M _n ratio is 9 by GPC.
It was 7.

Example 2 100 cm ³ diesel oil, 50 mmol of triethylaluminum and Example 8g component b) the 150d of treated according 1b of
placed in a container of m ^3. Then 0.6 m ³ / h of ethylene and the required amount of H ₂ to obtain a H ₂ concentration of 75% by volume are introduced at a temperature of 85 ° C. 0.2 dm ³ of butene-1 is metered in at the same time. After 2.5 hours, the polymerization is stopped at a pressure of 8 bar by depressurization. In the second reaction stage, 0.7 m ³ / h of ethylene and the amount of H ₂ necessary to obtain a H ₂ concentration of 2% are introduced. 1dm ³
Of butene-1 at the same time. The polymerization is stopped after 3 hours. The suspension is filtered and the polymer is dried by passing hot nitrogen through it. 31 kg of product are obtained.

The polyethylene powder has a VN of 290 cm ³ / g. The density is 0.945 g / cm ³ . 0.6g / 10min MFI 190/5, MFI 19
The ratio between 0 / 21.6 and MFI 190/5 is 22.

Example 3 Component a) is prepared as in Example 1a and the suspension medium is eliminated. This storage-stable solid is suspended in a hydrocarbon and treated as in Example 1b. Polymerization as described in Example 1c gives 149 g of polymer. This corresponds to a catalyst-time yield of 9.9 kg (PE) / mmol (Ti) .h. This polymer has a melt flow index MFI 1 of 5.2 g / 10 min.
It has a melt flow index ratio between MFI 190 / 21.6 and MFI 190/5 of 90/5 and 11.0.

Dispersed in ethylated N ₂ atmosphere diesel oil fraction in 1 dm ³ of - Comparative Example dropping funnel, a stirrer, 4-neck, round magnesium in a flask 114.3g of reflux condenser and 2 dm ³ equipped with a thermometer . 332 g of TiCl ₄ are added dropwise to this dispersion over 5.5 hours. The suspension medium is changed repeatedly until the liquid phase no longer contains titanium. 6 cm ³ of TiCl ₄ are added and the suspension is stirred at 125 ° C. Concentration in the liquid phase, after 18 hours was 28 mmol / dm ^3, further after 4 hours 27 mmol / dm ³
And still 24 mmol / d after a total of 60 hours of heat treatment
It was m ^3. The solid is washed once more with a hydrocarbon, then pretreated and polymerized as described in Example 1.

Analytical composition of the catalyst: Ti 5.3% by weight Mg 23.5% by weight Cl 71.2% by weight 160 g of polyethylene are obtained by polymerization. This polymer is obtained by mixing 3.1 g / 10 min MFI 190/5 and 11 MFI 190 / 21.6 with MF
It has a melt flow index ratio of I 190/5.

Example 4 100 cm ³ of diesel oil, 40 mmol of triethylaluminum and 1.2 g of component a) treated according to Example 1b
Place in 0 dm ³ container. Then 6.4 kg / h of ethylene and the required amount of H ₂ to obtain a concentration of 36% by volume are introduced at a temperature of 85 ° C. After 4 hours, the polymerization was depressurized to 6.6 bar
Stop at the pressure of The suspension is filtered and the polymer is
Dry by passing hot nitrogen through it. 25.5 kg of product are obtained. This corresponds to a catalyst yield of 21 kg / g (catalyst). This polymer has an MFI 190/5 of 0.8 g / 10 min and a ratio of 13 MFI 190 / 21.6 to MFI 190/5.

Examples 5 to 7 Table 1 shows the polymerization results obtained in the same manner as in Example 4 using butene, propene and hexene as comonomers.

Claims (2)

(57) [Claims] 1. A compound of the formula R ⁴ —CH ＝ CH ₂ wherein R ⁴ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. The reaction product of a magnesium alcoholate and titanium tetrachloride (component a) in suspension or in the gas phase at a temperature of from 20 to 200 ° C. and a pressure of from 0.5 to 50 bar For the production of poly-1-olefins by polymerization in the presence of a catalyst comprising an organometallic compound of a Group I-III metal of the Periodic Table (component b) And titanium tetrachloride in a hydrocarbon at a temperature of 50-100 ° C., then a portion of the soluble components are separated off and the resulting solid is subjected to a second reaction stage at 110-200 ° C. A process for producing poly-1-olefins as described above, wherein the polymerization is carried out in the presence of a catalyst which has produced component a) by subjecting it to a heat treatment at a temperature for 8 to 100 hours. 2. The method according to claim 1, wherein in the first reaction step the magnesium is represented by the formula Mg (OR) _{2 wherein} R is the same or different and is an alkyl group having 1 to 6 carbon atoms. Alcoholate and titanium tetrachloride in hydrocarbons
The reaction is carried out at a temperature of 50 to 100 ° C., then some of the soluble components are separated off and the resulting solid is subjected to a heat treatment at a temperature of 110 to 200 ° C. for 8 to 100 hours in a second reaction stage. The process according to claim 1, wherein component a) is produced.